Chinese telegraph code

The Chinese Telegraph Code, Chinese Telegraphic Code, or Chinese Commercial Code (simplified Chinese: 中文电码; traditional Chinese: 中文電碼; pinyin: Zhōngwén diànmǎ or simplified Chinese: 中文电报码; traditional Chinese: 中文電報碼; pinyin: Zhōngwén diànbàomǎ) is a four-digit decimal code (character encoding) for electrically telegraphing messages written with Chinese characters.

A codebook is provided for encoding and decoding the Chinese telegraph code. It shows one-to-one correspondence between Chinese characters and four-digit numbers from 0000 to 9999. Chinese characters are arranged and numbered in dictionary order according to their radicals and strokes. Each page of the book shows 100 pairs of a Chinese character and a number in a 10×10 table. The most significant two digits of a code matches the page number, the next digit matches the row number, and the least significant digit matches the column number, with 1 being the column on the far right. For example, the code 0022 for the character 中 (zhōng), meaning “center,” is given in page 00, row 2, column 2 of the codebook, and the code 2429 for the character 文 (wén), meaning “script,” is given in page 24, row 2, column 9. The PRC’s Standard Telegraph Codebook (Ministry of Post and Telecommunications 2002) provides codes for approximately 7,000 Chinese characters.

Senders convert their messages written with Chinese characters to a sequence of digits according to the codebook. For instance, the phrase 中文信息 (Zhōngwén xìnxī), meaning “information in Chinese,” is rendered into the code as 0022 2429 0207 1873. It is transmitted using the Morse code. Receivers decode the Morse code to get a sequence of digits, chop it into an array of quadruplets, and then decode them one by one referring to the book.

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